The present invention relates to an air bag for use in a passenger safety restraint system and more particularly to an air bag folded in a manner to enhance its operation and improve occupant safety. In addition, the present invention finds specific application with vehicle safety air bags adapted to protect the passenger and middle occupant.
One such air bag is shown in the commonly assigned U.S. Pat. No. 5,022,675 which discloses a folding process that places a plurality of internal side pleats and folds in opposing sides of the air bag to initially reduce the width of the rather large passenger side air bag. Experience shows that using the internal side pleats and folds increases the time to fold an air bag. In addition, this folding technique also takes added time to verify that the pleats and folds are of the desired sizes they are not visible as they as internal. It is an object of the present invention to provide an improved method of folding while still retaining a high degree of occupant safety. As is known in the art the method of folding effects the way the air bag will unfold during deployment. A too aggressive deployment of the air bag will cause the air bag to unfold in a manner that it may impact the occupant causing what is called "bag slap". FIG. 23 which shows comparative inflation data at a fixed time (about 40 msec.) during the deployment process of the same air bag folded three different ways using the some type of gas generator. Numeral 150 shows the deployment characteristics, at this time, of an air bag folded by the method taught in the above U.S. Patent while numeral 152 shows the deployment characteristic of the air bag folded in accordance with the first embodiment of the present invention and numeral 154 shows the deployment charastic in accordance with the second embodiment of the invention. As can be seen from this figure the folding technique of the present invention causes the air bag to deploy slightly further away from the occupant diminishing the occupance of bag slap.
Accordingly the invention comprises an air bag and method of folding same, the air bag including material defining a top, front, and bottom portions and side panels and an open inlet end, comprising the steps of: securing the inlet end about a retainer, positioning the material so that is lays relatively flat with either the top or the bottom portion laid upon the folding surface and with a first portion of the air bag extending to the right of the first end, a second portion extending to the left of the second end of the retainer a middle portion therebetween, folding over the first portion inwardly, toward a second fold line, about a first fold line defining a first folded over portion; folding over the first folded over portion outwardly toward the first fold line about the second fold line, continuing folding the first portion about the first and second fold lines until the there is no longer enough material to be folded over either the first or a third fold line, repeating the above steps to fold the second portion of the air bag, positioning the folded over portions resulting from the folding of the first and second portions of the air bag parallel to one another, the material of the air bag in the folded over configuration farthest from the retainer defining a first end. Forming in the first end a plurality of pleats and folds forming a pleated end and placing the pleated end adjacent the retainer. Folding material extending from the pleated end against the pleated end and securing the air bag in its folded configuration.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.